Synthesis, in vitro, reactivity, and identification of 6-phenyl-3-hexen-2-one in human urine after kava-kava (Piper methysticum) ingestion.

This study describes the synthesis of 6 -phenyl-3-hexen-2-one, a proposed metabolite of kava-kava (kava, 'Awa, Yaqona, Piper methysticum Forst.), its reactivity with glutathione in vitro, and its isolation and identification, as its mercapturic acid adduct using LC/MS/MS, in the urine of two human subjects following their ingestion of kava. A possible metabolic pathway for the formation of this metabolite and its possible role in hepatotoxicity are also discussed.

Cocaine levels in sweat collection patches vary by location of patch placement and decline over time.

Sweat collection patches are used for drug abuse monitoring. We investigated the effect of sweat patch location (back and shoulder) on cocaine levels after controlled intravenous cocaine exposure (210 mg/70 kg) in 12 subjects (Experiment 1). Gas chromatographic-mass spectrometric analyses show cocaine and metabolites levels in Pharmchek trade mark patches were eightfold higher on the back than those on the shoulders. To assess the mechanisms for possible loss of cocaine from patches during wear, 48 sweat patches with a small amount of cocaine-d(5) (100 ng as base/patch) were placed on the backs of eight cocaine-naive volunteers for up to 72 h (Experiment 2). Drug-free patches were applied over eight of the cocaine-d(5) (100 ng) containing patches to measure loss through the patch. Cocaine levels in spiked patches declined over time (p = 0.002), with levels at 48 h postapplication 30% less than control, consistent with possible drug reabsorption. Cocaine was detectable (> 2 ng/patch, LOQ) in four of eight initially cocaine-free patches placed on top of the cocaine-containing patches, indicating transfer through the patch outer membrane. Conversion to benzoylecgonine was detectable but at low levels (< 2%). Reabsorption (back transfer), degradation or hydrolysis, and loss of cocaine to the environment may account for substantial loss of cocaine from skin sweat collection patches during patch wear.

Kava does not display metabolic toxicity in a homogeneous cellular assay.

To determine whether kava (Kava kava, 'Awa, Yaqona, Piper methysticum Forst.), the popular herbal product associated recently with possible human hepatotoxicity, is bioactivated by cytochrome P450 enzymes to cytotoxic metabolites, three kava lactones (methysticin, yangonin, and desmethoxyyangonin) and an ethanolic extract of dried kava root were incubated over time in culture with MCL-5 cells, a human lymphoblastoid cell line that has been stably transfected with five human P450's (CYP 1A1, 1A2, 2A6, 2E1, and 3A4) and human epoxide hydrolase. Incubations were performed concurrently with a control cell line (cH2) that is derived from the same parental line as MCL-5, but transfected with two empty vectors. The kava compounds displayed varying degrees of toxicity (IC (50) values ranged from 50 to > 100 microM) to the MCL-5 and cH2 cell lines; however, both cell lines were equally sensitive to the test compounds. These results suggest that the parent compound for each of the four test compounds was primarily responsible for the observed cell toxicity and that CYP 1A1, 1A2, 2A6, 2E1, and 3A4 or epoxide hydroxylase did not appear to be involved. Thus, in vitro kava does not appear to be activated to toxic metabolites by enzymes known to be important in metabolic toxicity.

16alpha-Bromo-epiandrosterone therapy modulates experimental feline immunodeficiency virus viremia: initial enhancement leading to long-term suppression.

16alpha-Bromo-epiandrosterone (epiBr), a synthetic derivative of the natural hormone dehyroepiandrosterone (DHEA), was evaluated for its effects on feline immunodeficiency virus (FIV) infection in experimental cats. The rationale for this study was based on the ability of DHEA to significantly reduce the mortality to viral infections in mice. DHEA and epiBr also have demonstrable in vitro anti-viral activity for both HIV-1 and FIV. Preliminary pharmacokinetic studies in cats demonstrated that subcutaneously injected epiBr was rapidly absorbed, completely metabolized, and nontoxic. Metabolites were excreted in both urine and feces, with the latter having the most complex pattern of breakdown products. Cats were then divided into four groups; two groups were infected with FIV and two uninfected. Two groups, one infected and one uninfected were treated on 5 consecutive days of weeks 0, 4, 8, 12 and 16 with epiBr. The remaining two groups were mock treated with the drug vehicle alone. Treatment started 1 week prior to infection and extended for 4 weeks after infection. Cats were observed for 20 weeks post-FIV infection. Infected cats had identical decreases in blood neutrophil and lymphocyte counts following, regardless of whether they were treated with epiBr or vehicle alone. The CD4/CD8 T-cell ratio was decreased following FIV exposure, but was significantly more decreased for the epiBr treated animals from week 2 post-infection onward. CD4+ T cells were decreased in FIV-infected cats treated with epiBr compared to their untreated cohort, while CD8+ T cells tended to be higher in treated animals. FIV infected cats that were treated with epiBr had over one-log higher virus loads at week 2 post-infection than non-epiBr treated cohorts. In spite of this enhanced initial viremia, the subsequent levels of virus in the blood were significantly lower in epiBr treated versus untreated animals. EpiBr treated cats had significantly higher FIV-p24 antibody responses than control cats receiving vehicle alone, although primary and secondary antibody responses to a T-cell dependent non-FIV antigen, keyhole limpet hemocyanin (KLH), were unaffected. EpiBr treatment significantly decreased the expected FIV-induced suppression of IL-12 p40 mRNA levels in peripheral blood mononuclear cells (PBMCs) observed at weeks 4, 5, 8, 9 and 16 post-infection, but had no influence on FIV-induced changes in IL-4, IL-6, IL-10, IFN-gamma, MIP-1alpha and RANTES.

Disposition of cocaine in skin, interstitial fluid, sebum, and stratum corneum.

The aim of this study was to determine whether or not the skin acts as a reservoir for cocaine. Cocaine-d5 (1 mg/kg) was administered to five nondependent, cocaine-experienced volunteers. Skin tissue, interstitial fluid, sebum, stratum corneum, and plasma were collected for 72 h after drug administration. Cocaine and benzoylecgonine (BE) levels were determined using GC-MS. Cocaine concentrations peaked in plasma at 1 h after administration, with pharmacokinetic parameters (t(1/2), CL, Vd) also in the expected ranges. In skin, cocaine levels peaked around 1.5 h after administration and became undetectable by 6 h. A correlation was found between the plasma and skin AUC for cocaine (R = 0.99, p = 0.006, N = 4). BE was not detected in skin. In interstitial fluid (N = 4), cocaine concentrations peaked around 5 h after drug administration and were undetectable by 24 h. BE peaks varied between 2 and 24 h and were not detectable at 48 h. In sebum, cocaine levels peaked between 3 and 24 h. BE was found in three samples between 12 and 24 h. In stratum corneum, cocaine was measurable in only one sample from one subject. These findings suggest that skin does not act as a reservoir for cocaine. Rather, cocaine appears to be distributed rapidly to the skin and eliminated, following a time course similar to that of plasma.